I do not know much about QLD and I think it is pretty different to NSW. But

I would check you cooling off rights as in once the contract is exchanged when what time period do you have to change your mind e.g 5 days, 2 weeks and what is the penalty.

Also I think you should see if you contract has a finance clause that is you have until say two weeks to get your finance in order after the date of contract and if for whatever reason you are denied can you get out of the contract.

Can you speak to a solicitor before you sign anything as I think most agents just want the sale and is it too late for you to go to a bank direct and cut out the mortgage broker (I personally hate them).